Back in the 1970's-80's a large quantity of "cleaned" Israeli surplus 9mm ammo came in the U.S. that was marked "sold for components only!" and us purchasers had to sign a document that stated that we would not fire it in anything and that we would pull the tips for reloading.
This ammo was surplused because it was stored in crates, left outside in Israel in the hot sun! (Heat is B-A-D for storage of ammo!)
The cases had been "cleaned" I think by either tumbling (also dangerous as it changes the physical structure of the powder!) or acid-cleaning and it removed any coloring on the bullet tips so that when "someone" fired this ammo through an UZI one never knew if there were tracers in the 1000-rd loose packed cartons!
And yes, I have seen what happened when someone would fire this ammo ina pistol!